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Water Authority moving ahead with digester plan

Preliminary audit will be conducted

The Altoona Water Authority has given the go-ahead for a preliminary energy savings “audit” that could lead to creation of a digester operation at its sewer plants — producing gas that could heat the plants, be sold to the gas company or be used to generate electricity — which could power the plants or be sold to the grid.

The audit will be performed by Energy Systems Group, chosen from among four energy service companies that bid for the work, which is conducted under a loan program administered by the Pennsylvania Sus­tain­able Energy Fund, a partnership between the Treasury Department and the Founda­tion for Renew­able Energy and Environment.

The program operates under a law that requires that participating firms fulfill 90 percent of their preliminary audit estimates of savings and that projects at least break even during their payback periods, which means that benefits are free and clear after debt service ends.

All four candidate firms — and another that dropped out due to staffing problems — predicted that changes at the plants could generate worthwhile savings — with three of the firms predicting annual benefits of $1.5 million.

The company bears all the costs of a preliminary audit, and ordering such an audit places the authority under no obligation, according to Jim Balliet, consulting engineer with Gwin Dobson & Foreman.

If the preliminary audit shows that it would be worthwhile to pursue a “project” — which would include all possible energy savings measures, including commonplace ones like replacing regular lighting with LED equipment and outdated heating with high-efficiency furnaces — the firm would propose an “investment grade audit.”

Consenting to an investment grade audit would commit the authority to some expense, according to Balliet.

That expense would be “rolled in” to a project, if the authority agrees to one, and would be negotiated with the firm if the authority backs out at that point, according to Todd Musser, authority director of water treatment operations.

So far, under the law that set up the program in Pennsylvania a few years ago, no preliminary audit has failed to generate a project, said Brian Book, a consulting engineer from cb3 Solutions LLC in Bellefonte.

Balliet, Book and the staff recommended ESG because its team includes an engineer familiar with the authority’s plants and the company has done successful projects in Pennsylvania on plants that operate similar systems.

One concern is that any operational changes not interfere with regular plant operations, Balliet said.

Digester operations, which involve importing high-energy food waste to mix with the regular sewage — are becoming more common because it is becoming increasingly difficult to landfill and otherwise dispose of sewer sludge.

“Places have started to refuse (the sludge),” Balliet said.

The preliminary audit will probably include a study of the availability of food waste for importation, Balliet said.

Given that there is no obligation after the preliminary audit, the authority can use the information thus provided as it sees fit, if it decides to proceed no further, officials said, when asked by authority member Marla Marcinko.

It would not be sporting, however, to try to engage two companies in a preliminary audit, to get the benefit of both companies’ expertise, as such can cost in the hundreds of thousands of dollars and companies don’t expect to be competing at that point, Musser said, in answer to a question from board member Omar Strohm.

Mirror Staff Writer William Kibler is at 949-7038.

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